Startup Stash - A curated directory of 400 resources & tools for startups
Intercom on Product Management - The ultimate resource for aspiring product managers
Freebiesjedi - Discover & download useful freebies everyday
The Product Management guide - A book on how to create and ship products that people love
Freebie.Supply - Awesome free things for entrepreneurs & startups
Software Product Management Stack - Resources & tools to help you manage your software product